INDIANAPOLIS - The New Orleans Saints have long believed that a team can't have too many quality running backs, but that point was painfully driven home last season when they were down to their eighth tailback by the end of their playoff game at Seattle.

"I think we had 13 guys through the door last year at one time or another," said the Saints' director of college scouting, Rick Reiprish, during a break at the NFL Scouting Combine on Friday. "Then, whenever one of them would really get going, he'd get nicked."

The Saints will look to add quality and depth to their backfield heading into the 2011 season, especially with the uncertain contract status of veteran starters Pierre Thomas and Reggie Bush.

What's less clear is how much they would invest in any one back.

One school of thought is the Saints should target a physical runner such as Alabama's Mark Ingram in the first round of the draft. Another is to avoid the position until later rounds, because NFL tailbacks are so susceptible to injuries.

Although there are great success stories, such as Chris Johnson in Tennessee and Adrian Peterson in Minnesota, the list of recent first-round tailbacks is littered with players who have battled nagging injuries -- from Ryan Mathews in 2010 to Knowshon Moreno, Donald Brown and Beanie Wells in 2009 to Darren McFadden and others in the 2008 class.

"We never shy away from (a specific position). Any player can get hurt on any given play. You can never worry about that," said Pittsburgh Steelers director of football operations Kevin Colbert, who has lived through both the risk and reward of drafting tailback Rashard Mendenhall in the first round in 2008.

A shoulder injury limited Mendenhall to four games as a rookie before he eventually bloomed into a driving force behind their Super Bowl run last month.

"Running backs will get hurt because they get hit so often and so hard," Colbert said. "But you still hope your guys will stay healthy, and Rashard has shown he can be a healthy, productive running back."

The Super Bowl champion Green Bay Packers haven't drafted a tailback in the first round in more than 20 years, although General Manager Ted Thompson insisted that there's no mandate to avoid them in Green Bay.

"We never looked at that position as saying, 'You absolutely can't do that,' " said Thompson, who learned at the feet of legendary former Packers general manager Ron Wolf. "I know what you're saying (about injury risk), but good running backs are hard to find. And if you're able to get one, you can add a lot of value to your team. There's a lot of examples we could go through the league doing that."

Each tailback needs to be evaluated on a case-by-case basis, and it appears likely that some team will deem Ingram worth the risk in the top 20 picks -- although he is the only tailback being considered as a surefire first-round prospect.

Ingram, who said he measured at 5 feet, 9 inches, 215 pounds Friday, is drawing some comparisons to NFL all-time great Emmitt Smith, although he is a bit undersized for a "power runner."

"I'm a complete all-around back," said Ingram, who has been training in the New Orleans area this winter with local trainer Wyatt Harris at the Sonic Boom speed, conditioning and strength academy. "I could be in the game first down, second down, third down, goal line, short-yardage, pick up pass protections, go out of the backfield and catch the ball, things like that. So I'm a complete back."

As enticing as a proven and versatile back such as Ingram might be, many teams will still choose to shy away from the position early in the draft, and not just because of injury concerns.

There is also a popular belief among NFL talent evaluators that running backs can be "found" in later rounds and even on the street.

Reiprish said he believes that. It's hard to argue with him, considering the Saints have signed undrafted gems Thomas, Chris Ivory and Lynell Hamilton.

Last season, the two leading rookie rushers in the NFL were undrafted free agents -- Tampa Bay's LeGarrette Blount and Ivory. And the leading rusher in the league was Houston's Arian Foster -- who, by the way, had tentatively agreed to join the Saints after the 2009 draft before changing his mind a day later.

"In the top 10 of the draft, you had better pick what you can't sign," said former general manager and current NFL Network analyst Michael Lombardi. "Running backs, you can find them. Look at Chris Ivory from Tiffin College. He comes in the NFL and plays very well for the Saints. Running backs can be found."

Tampa Bay Buccaneers General Manager Mark Dominik certainly proved that theory when his team scooped up Blount after he was released by the Tennessee Titans last summer. But Dominik doesn't completely buy into it.

"I'd like to think that (they can be found easily), but it still comes down to doing your due diligence," said Dominik. He said the common denominator between Ivory, Blount and Foster was that they're all physical runners who can break tackles but ran into some missteps in college on or off the field.

"When you go back and look at all three of those players in their college days, you see they were all very productive players," Dominik said. "They still showed you the blueprint that they were going to be talented."

In Ivory's case, part of the reason teams were scared off was because of his injury history in college, as well as some off-the-field concerns.

Clearly, there's no tried-and-true formula. Asked if one can identify tailbacks who are bigger injury risks than others, Reiprish recalled the case of former Georgia and Denver Broncos tailback Terrell Davis, who couldn't stay on the field in college, then turned into an MVP, 2,000-yard rusher and Super Bowl hero in the pros.

The Saints' scouting staff will be doing more than its due diligence at the tailback position heading into this year's draft -- scouring the list of prospects from potential first-rounders to potential undrafted free agents.

Because the one thing they know for sure about the tailback position is that they can never have enough quality options from which to choose.